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The use of US FDA-approved drugs is preferred due to the need for lower costs and less time. In in silico medicine, repurposing is a quick and accurate way to screen US FDA-approved medications to find a therapeutic option for COVID-19 infection. Dual inhibitors possess dual inhibitory activity, which may be due to the inhibition of two different enzymes, and are considered better than combination therapy from the developmental and clinical perspectives. In this study, a molecular docking simulation was performed to identify the interactions of antiviral drugs with the critical residues in the binding site of the main SARS-CoV-2 protease, spike glycoprotein, and papain-like protease receptors compared to the angiotensin-converting enzyme-related carboxypeptidase (ACE2) receptor of host cells. Each of the receptors was docked with 70 US FDA-approved antiviral drugs using AutoDock Vina. A molecular dynamics (MD) simulation study was also used for 100 ns to confirm the stability behaviour of the ligand receptor complexes. Among the drugs that had the strongest interaction with the SARS-CoV-2 main protease, spike glycoprotein and papain-like protease receptors, and host cell ACE2 receptors, Simeprevir, Maraviroc and Saquinavir had dual inhibitory effects. The MD simulation study confirmed the stability of the strongest interactions between the antiviral drugs and the main protease, ACE2, spike glycoprotein, and papain-like protease receptors to 100 ns. However the results of MMPBSA analysis showed that the bond between Saquinavir and the ACE2 receptor was weak. Simeprevir and Maraviroc drugs had acceptable binding energies with dual receptors, especially the Simeprevir.Communicated by Ramaswamy H. Sarma.

Since the onset of the global epidemic of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), whole genome sequencing of virus in all countries has been considered to track and predict virus transmission and variation patterns. In the current study we reported a novel complete genome sequence of SARS-CoV-2 isolated from Iran. Genomics variations and protein sequences were evaluated for the isolated sequence and seven Iranian complete genome sequences of SARS-CoV-2 from NCBI using the reference genome of the SARS-CoV-2 Wuhan-Hu-1. The results showed six nucleotide substitutions. The multiple sequence alignment of the spike protein of the Wuhan-Hu-1 strain and the emerging variants indicated similar its residue pattern in the current sequence to the Wuhan-Hu-1 strain. There were relatively similar binding affinity and residues involved in the interactions of the spike receptor-binding domain (RBD) of the Wuhan-Hu-1 strain, the variants and Hormozgan With angiotensin-converting enzyme 2 (ACE2). Tracing the phylogeny of virus indicated distinct clustering of Iranian variants in branches close to the Asian countries. The mutation effect study on the function of proteins predicted neutral impact of all six nucleotide substitutions. However, the free energy calculations indicated a decreasing the protein stability related to the mutations. This data, consistent with similar studies, showed that despite the high similarity in the nucleotide sequence of the SARS-CoV-2, the mutation pattern varies from country to country. Therefore, any country can benefit from these studies to track and find appropriate strategies for treating and controlling the epidemic.Communicated by Ramaswamy H. Sarma.

Monkeypox is a zoonotic virus that has recently affected different countries worldwide. On July 23, 2022, the WHO declared the outbreak of monkeypox as a public health emergency of international concern. Surveillance studies conducted in Central Africa in the 1980s and later during outbreaks in the same region showed smallpox vaccines to be clinically somewhat effective against Monkeypox virus. However, there is no specific vaccine against this virus. This research used bioinformatics techniques to establish a novel multi-epitope vaccine candidate against Monkeypox that can induce a strong immune response. Five well-known antigenic proteins (E8L, A30L, A35R, A29L, and B21R) of the virus were picked and assessed as possible immunogenic peptides. Two suitable peptide candidates were selected according to bio-informatics analysis. Based upon in silico evaluation, two multi-epitope vaccine candidates (ALALAR and ALAL) were built with rich-epitope domains consisting of high-ranking T and B-cell epitopes. After predicting and evaluating the 3D structure of the protein candidates, the most efficient 3D models were considered for docking studies with Toll-like receptor 4 (TLR4) and the HLA-A * 11:01, HLA-A*01:01, HLA-A*02:01, HLA-A*03:01, HLA-A*07:02, HLA-A*15:01, HLA-A*30:01 receptors. Subsequently, molecular dynamics (MD) simulation of up to 150 nanoseconds was employed to assess the durability of the interaction of the vaccine candidates with immune receptors. MD studies showed that M5-HLA-A*11:01, ALAL-TLR4, and ALALAR-TLR4 complexes were stable during simulation. Analysis of the in silico outcomes indicates that the M5 peptide and ALAL and ALALAR proteins may be suitable vaccine candidates against the Monkeypox virus.Communicated by Ramaswamy H. Sarma.

Human T cell leukemia virus type-1 (HTLV-1) is the cause of adult T cell leukemia/lymphoma (ATL), uveitis, and certain pulmonary diseases. In recent decades, many scientists have proposed the development of different treatment and prevention strategies to combat HTLV-1 infection. In this study, we used bioinformatics tools to predict peptide and protein vaccine candidates against HTLV-1 that can potentially induce antibody production and both CD4+ and CD8+ T cell immune responses. Five critical proteins, viz., Hbz, Tax, Pol, Gag , and Env, were analyzed for predicting immunogenic T and B cell epitopes and subsequently evaluated using bioinformatics tools. Based on the predictions, the most antigenic epitopes were selected, and their interaction with immune receptors was investigated. We also designed a protein vaccine candidate with an eight-epitopes-rich domain, including overlapping epitopes detected on both B and T cells. Then, the interaction of the epitope and the designed protein with immune receptors was validated in an in silico docking study. The docking analysis showed that the O2 epitope and D8 protein interact strongly with immune receptors, especially the HLA-A*02:01 receptor. The stability of the interactions was investigated by molecular dynamics (MD) for 100 ns. The root mean square deviation, radius of gyration, hydrogen bonds, and solvent-accessible surface area were calculated for the 100 ns trajectory period. MD studies demonstrated that the O2-HLA-A*02:01 and D8-HLA-A*02:01 complexes were stable during the simulation. Analysis of in silico results showed that the peptide and the designed protein could elicit humoral and cell-mediated immune responses.Communicated by Ramaswamy H. Sarma.